An experimental investigation on fatigue crack growth of AL6XN stainless steel

✍ Scribed by S. Kalnaus; F. Fan; A.K. Vasudevan; Y. Jiang

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 759 KB
• Volume: 75
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/j.engfracmech.2007.11.002

✦ Synopsis

The crack growth behavior of AL6XN stainless steel was experimentally investigated using round compact tension (CT) specimens. The influences of the R-ratio (the ratio of the minimum load over the maximum applied load in a cycle), the tensile and compressive overloads, and the loading sequence on crack growth were studied in detail. The results from the constant-amplitude experiments show a sensitivity of the crack growth rate to the R-ratio. The application of a tensile overload has a profound effect on crack growth, resulting in a significant retardation in the crack propagation rate. A compressive overload (underload) leads to a short-lived acceleration in crack growth. Results from the two-step high-low loading reveal a period of crack growth retardation at the beginning of the lower amplitude step, an effect similar to that of a single overload. A crack driving force parameter together with a modified Wheeler model is found to correlate the crack growth experiments well.